Merck Manual

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Christopher J. Brady

, MD, Wilmer Eye Institute, Retina Division, Johns Hopkins University School of Medicine

Last full review/revision Jul 2019| Content last modified Jul 2019
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Proptosis is protrusion of the eyeball. Exophthalmos means the same thing, and this term is usually used when describing proptosis due to Graves disease. Disorders that may cause changes in the appearance of the face and eyes that resemble proptosis but are not include hyperthyroidism without infiltrative eye disease, Cushing disease, and severe obesity.


The most common cause in adults is Graves disease (see table Some Causes of Proptosis), which causes edema and lymphoid infiltration of the orbital tissues.

The most common cause in children is orbital cellulitis.


Some Causes of Proptosis


Suggestive Findings

Diagnostic Approach

Eye symptoms: Eye pain, lacrimation, dry eyes, irritation, photophobia, ocular muscle weakness causing diplopia, vision loss caused by optic nerve compression

Systemic symptoms: Palpitations, anxiety, increased appetite, weight loss, insomnia, goiter, pretibial myxedema (see Hyperthyroidism)

Thyroid function tests

Sometimes CT or MRI

Carotid-cavernous sinus or dural-cavernous sinus fistula

Pulsating proptosis with an orbital bruit

Magnetic resonance angiography

Ophthalmoplegia, headache, ptosis, decreased visual acuity, fever


Tearing, blepharospasm, redness

Intraocular pressure measurement and fundoscopy by ophthalmologist

Redness, fever, pain, impaired visual acuity, impaired or painful extraocular movements

Usually unilateral


Orbital tumors (eg, lymphoma, hemangioma, vascular malformations)

Decreased visual acuity, diplopia, pain


Retrobulbar hemorrhage, orbital compartment syndrome

Decreased visual acuity, diplopia, pain, ophthalmoplegia, risk factors

Immediate CT or treatment based on clinical findings

Spheno-orbital meningioma

Pain, headache, visual field defects, ophthalmoplegia



Rate of onset may provide a clue to diagnosis. Sudden unilateral onset suggests intraorbital hemorrhage (which can occur after surgery, retrobulbar injection, or trauma) or inflammation of the orbit or paranasal sinuses. A 2- to 3-week onset suggests chronic inflammation or orbital inflammatory pseudotumor (non-neoplastic cellular infiltration and proliferation); slower onset suggests an orbital tumor.

Ocular examination findings typical of hyperthyroidism but unrelated to infiltrative eye disease include eyelid retraction, eyelid lag, temporal flare of the upper eyelid, and staring. Other signs include eyelid erythema and conjunctival hyperemia. Prolonged exposure of larger-than-usual areas of the eyeball to air causes corneal drying and can lead to infection and ulceration.

Red flags

The following findings are of particular concern:

  • Eye pain or redness

  • Headache

  • Loss of vision

  • Diplopia

  • Fever

  • Pulsating proptosis

  • Neonatal proptosis


Proptosis can be confirmed with exophthalmometry, which measures the distance between the lateral angle of the bony orbit and the cornea; normal values are < 20 mm in whites and < 22 mm in blacks. CT or MRI is often useful to confirm the diagnosis and to identify structural causes of unilateral proptosis. Thyroid function testing is indicated when Graves disease is suspected.


Lubrication to protect the cornea is required in severe cases. When lubrication is not sufficient, surgery to provide better coverage of the eye surface or to reduce proptosis may be required. Systemic corticosteroids (eg, prednisone 1 mg/kg orally once a day for 1 week, tapered over 1 month) are often helpful in controlling edema and orbital congestion due to thyroid eye disease or inflammatory orbital pseudotumor. Other interventions vary by etiology. Graves exophthalmos is not affected by treatment of the thyroid condition but may lessen over time. Tumors must be surgically removed. Selective embolization or, rarely, trapping procedures may be effective in cases of arteriovenous fistulas involving the cavernous sinus.

Key Points

  • The most common cause of bilateral proptosis in adults is Graves disease.

  • Acute unilateral proptosis suggests infection or vascular disorder (eg, hemorrhage, fistula, cavernous sinus thrombosis).

  • Chronic unilateral proptosis suggests tumor.

  • Do CT or MRI and thyroid function testing when Graves disease is suspected.

  • Apply lubrication to exposed cornea.

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